SIMBAD references

2018MNRAS.473.2304P - Mon. Not. R. Astron. Soc., 473, 2304-2323 (2018)

NuSTAR + XMM-Newton monitoring of the neutron star transient AX J1745.6-2901.

PONTI G., BIANCHI S., MUNOZ-DARIAS T., MORI K., DE K., RAU A., DE MARCO B., HAILEY C., TOMSICK J., MADSEN K.K., CLAVEL M., RAHOUI F., LAL D.V., ROY S. and STERN D.

Abstract (from CDS):

AX J1745.6-2901 is a high-inclination (eclipsing) transient neutron star (NS) low-mass X-ray binary showcasing intense ionized Fe K absorption. We present here the analysis of 11 XMM-Newton and 15 NuSTAR new data sets (obtained between 2013 and 2016), therefore tripling the number of observations of AX J1745.6-2901 in outburst. Thanks to simultaneous XMM-Newton and NuSTAR spectra, we greatly improve on the fitting of the X-ray continuum. During the soft state, the emission can be described by a disc blackbody (kT ∼ 1.1-1.2 keV and inner disc radius rDBB ∼ 14 km), plus hot (kT ∼ 2.2-3.0 keV) blackbody radiation with a small emitting radius (rBB ∼ 0.5 - 0.8 km) likely associated with the boundary layer or NS surface, plus a faint Comptonization component. Imprinted on the spectra are clear absorption features created by both neutral and ionized matter. Additionally, positive residuals suggestive of an emission Fe K α disc line and consistent with relativistic ionized reflection are present during the soft state, while such residuals are not significant during the hard state. The hard-state spectra are characterized by a hard (Γ ∼ 1.9-2.1) power law, showing no evidence for a high energy cut-off (kTe > 60-140 keV) and implying a small optical depth (τ < 1.6). The new observations confirm the previously witnessed trend of exhibiting strong Fe K absorption in the soft state that significantly weakens during the hard state. Optical (GROND) and radio (GMRT) observations suggest for AX J1745.6-2901 a standard broad-band spectral energy distribution as typically observed in accreting NSs.

Abstract Copyright:

Journal keyword(s): accretion - accretion discs - methods: observational - techniques: spectroscopic - stars: neutron - absorption lines - X-rays: binaries

Simbad objects: 7

goto Full paper

goto View the references in ADS

To bookmark this query, right click on this link: simbad:2018MNRAS.473.2304P and select 'bookmark this link' or equivalent in the popup menu